The door lock actuators activating?

2000 Oldsmobile Alero mileage: 45,000. As I am driving, my door lock actuators keep activating to lock the doors. They activate every two to three seconds. But sometimes they stop (and behave normal). Sometimes they seem to activate when I hit a bump, but other times I don't really hit any bumps when they activate. This occurs only while the car is moving. When stopped at an intersection, the locks don't do anything. I have not noticed any other problems locking or unlocking the doors when the car is stopped/parked. Also, in conjunction with this, when stopped at an intersection, the interior dome light comes on. Then goes off once I start moving, but then the doors start locking again. Additionally, when I park and get out, the interior lights do not always go off sometimes they stay on for many minutes, sometimes they go off in about twenty seconds (as normal). Sometimes re-closing the doors fix this, sometimes not. Any advice is much appreciated. Thank You!